title: LIN28B-mediated expression of fetal hemoglobin and production of fetal-like erythrocytes from adult human erythroblasts ex vivo.
abstract: Reactivation of fetal hemoglobin (HbF) holds therapeutic potential for sickle cell disease and β-thalassemias. In human erythroid cells and hematopoietic organs, LIN28B and its targeted let-7 microRNA family, demonstrate regulated expression during the fetal-to-adult developmental transition. To explore the effects of LIN28B in human erythroid cell development, lentiviral transduction was used to knockdown LIN28B expression in erythroblasts cultured from human umbilical cord CD34+ cells. The subsequent reduction in LIN28B expression caused increased expression of let-7 and significantly reduced HbF expression. Conversely, LIN28B overexpression in cultured adult erythroblasts reduced the expression of let-7 and significantly increased HbF expression. Cellular maturation was maintained including enucleation. LIN28B expression in adult erythroblasts increased the expression of γ-globin, and the HbF content of the cells rose to levels >30% of their hemoglobin. Expression of carbonic anhydrase I, glucosaminyl (N-acetyl) transferase 2, and miR-96 (three additional genes marking the transition from fetal-to-adult erythropoiesis) were reduced by LIN28B expression. The transcription factor BCL11A, a well-characterized repressor of γ-globin expression, was significantly down-regulated. Independent of LIN28B, experimental suppression of let-7 also reduced BCL11A expression and significantly increased HbF expression. LIN28B expression regulates HbF levels and causes adult human erythroblasts to differentiate with a more fetal-like phenotype.
authors.affiliation: Molecular Genomics and Therapeutics Section, Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases/NIH, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Y Terry
authors.initials: YT
authors.lastname: Lee
authors.forename: Jaira F
authors.initials: JF
authors.lastname: de Vasconcellos
authors.forename: Joan
authors.initials: J
authors.lastname: Yuan
authors.forename: Colleen
authors.initials: C
authors.lastname: Byrnes
authors.forename: Seung-Jae
authors.initials: SJ
authors.lastname: Noh
authors.forename: Emily R
authors.initials: ER
authors.lastname: Meier
authors.forename: Ki Soon
authors.initials: KS
authors.lastname: Kim
authors.forename: Antoinette
authors.initials: A
authors.lastname: Rabel
authors.forename: Megha
authors.initials: M
authors.lastname: Kaushal
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Muljo
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Miller
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism; D024401:Carbonic Anhydrase I / Q000378:metabolism; D018929:Cell Culture Techniques; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004900:Erythroblasts / Q000166:cytology*; D004912:Erythrocytes / Q000166:cytology*; D005312:Fetal Blood / Q000166:cytology; D005319:Fetal Hemoglobin / Q000378:metabolism*; D005786:Gene Expression Regulation; D006441:Hemoglobin A / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism; D010641:Phenotype; D016601:RNA-Binding Proteins
chemical_list: D018952:Antigens, CD34; D004268:DNA-Binding Proteins; C516326:LIN28B protein, human; C541492:MIRN96 microRNA, human; D035683:MicroRNAs; D016601:RNA-Binding Proteins; C487931:mirnlet7 microRNA, human; D006441:Hemoglobin A; D005319:Fetal Hemoglobin; D017351:N-Acetylglucosaminyltransferases; D024401:Carbonic Anhydrase I